Injection blow molding system with enhanced heat transfer channel configuration

ABSTRACT

An injection blow molding (IBM) system and method for controlling the surface temperature of the parison molds by passing heat transfer fluid through a plurality of fluidly-coupled heat transfer channels. The heat transfer channels can be formed primarily in die sets to which the parison molds are attached. The placement and distribution of the heat transfer channels relative to the parison-forming surfaces helps control the temperatures of the bodies and necks of the parisons being formed, instead of relying on various adjustments by an IBM operator. This system/method reduces the discretion required by the IBM operator and shifts the burden of consistently making high-quality parisons and molded articles onto the designer of the IBM tooling.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Embodiments of the present invention relate to an injection blow moldingapparatus and method for forming molded articles.

2. Description of the Related Art

Injection blow molding (IBM) is a technique used for creating variouscontainers such as plastic bottles for medication or other contents. TheIBM process is performed with an IBM machine that first injection moldsa resin into a plurality of parisons of desired shapes and then blowmolds the parisons into the final molded articles.

An injection station of the IBM machine typically includes a splitparison mold assembly that defines a plurality of cavities within whichthe parisons are formed. In the injection molding stage of the IBMprocess, the parison-forming surfaces of the split parison mold areheated to and/or cooled to different temperatures via a plurality ofwater lines formed in the split parison mold near the parison-formingsurfaces. The water lines may be supplied with water at differenttemperatures depending on the location of the water line relative to theneck or body of the parison being formed. Typically, a plurality ofindividual thermolators are required to control the temperature of watersupplied to the various water lines in the parison mold and an operatoris required to use a significant amount of discretion in makingadjustments to the water temperature flowing through water lines atdifferent locations along the body and/or neck of the parison during theinjection blow molding process.

The operator discretion necessary to make certain parison mold designsfunction properly requires highly experienced IBM operators and canrequire significant trial and error in order to determine satisfactoryoperating parameters. Further, the complexity of manufacturing andoperating split parison molds with multiple water lines formed thereincan result in high capital costs, high operating costs, and highmaintenance costs.

Thus, it would be desirable to have an injection molding system and/orprocess where IBM operator discretion is minimized, trial-and-erroroperation of the IBM operator is minimized, and mold tooling design,fabrication, replacement, and maintenance costs are minimized.

SUMMARY OF THE INVENTION

Some embodiments of the invention disclose an injection blow moldingsystem for injection molding a resin into a plurality of parisons andblow molding the parisons into a plurality of molded articles. Theinjection blow molding system includes an injection station forinjection molding the resin into the parisons and a blowing station forblow molding the parisons into the molded articles. The system alsoincludes a heat transfer fluid source and an indexing head fortransferring the parisons from the injection station to the blowingstation. The injection station includes a split parison mold assemblyshiftable between an open position and a closed position. The splitparison mold assembly includes first and second body mold halves fordefining the exterior shape of the bodies of the parisons. The injectionstation defines one or more heat transfer channels coupled in fluid-flowcommunication with the heat transfer fluid source. In some embodimentsof the injection station, less than 50 percent of the total volume ofthe heat transfer channels is defined within the body mold halves.

Other various embodiments of the invention disclose an injection blowmolding system for injection molding a resin into a plurality ofparisons and blow molding the parisons into a plurality of moldedarticles. The injection blow molding system includes an injectionstation for injection molding the resin into the parisons and a blowingstation for blow molding the parisons into the molded articles. Theinjection blow molding system further includes a heat transfer fluidsource and an indexing head for transferring the parisons from theinjection station to the blowing station. The injection station includesfirst and second die sets shiftable between an open position and aclosed position and a split parison mold assembly coupled to the firstand second die sets. The split parison mold assembly defines a pluralityof parison cavities for receiving the resin when the die sets are in theclosed position. The injection station defines one or more heat transferchannels coupled in fluid-flow communication with the heat transferfluid source. At least a portion of the heat transfer channels aredefined within the first and second die sets.

Some embodiments of the invention disclose an injection blow moldingsystem for injection molding a resin into a plurality of parisons andblow molding the parisons into a plurality of molded articles. Theinjection blow molding system includes an injection station defining oneor more heat transfer channels and a heat transfer fluid source coupledin fluid-flow communication with the heat transfer channels. Theinjection station includes first and second die sets shiftable betweenan open position and a closed position and first and second mold halfassemblies coupled to the first and second die sets respectively. Thefirst and second mold half assemblies present respective first andsecond parison cavity surfaces that cooperatively define a plurality ofparison cavities when the die sets are in the closed position. At least50 percent of the total volume of the heat transfer channels is locatedin heat transfer channels that are spaced more than 1 inch from theparison cavity surfaces.

Other embodiments of the invention disclose an injection blow moldingprocess that includes a step of injection molding a resin into aplurality of parisons at an injection station. The injection moldingstep includes substeps of shifting a split parison mold assembly from anopen position to a closed position, then injecting the resin into aplurality of parison cavities cooperatively defined by parison cavitysurfaces of the split parison mold assembly when the split parison moldassembly is in the closed position. The injection molding step furtherincludes a substep of passing a heat transfer fluid through heattransfer channels defined within the injection station. At least 50percent of the total volume of the heat transfer channels is spaced morethan 1 inch away from the parison cavity surfaces. The injection blowmolding process also includes a step of transferring the parisons fromthe injection station to a blowing station, and a step of blow moldingthe parisons into molded articles at the blowing station.

This summary is provided to introduce a selection of concepts in asimplified form that are further described below in the detaileddescription. This summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used to limit the scope of the claimed subject matter. Other aspectsand advantages of the present invention will be apparent from thefollowing detailed description of the preferred embodiments and theaccompanying drawing figures.

BRIEF DESCRIPTION OF THE FIGURES

Embodiments of the present invention are described in detail below withreference to the attached drawing figures, wherein:

FIG. 1 is a block diagram of a system for producing blow moldedarticles, particularly illustrating an injection blow molding apparatusand systems for supplying resin and heat transfer fluid to an injectionstation of the injection blow molding apparatus;

FIG. 2 is a plan view of an injection blow molding apparatus,particularly illustrating the apparatus's injection station, blowingstation, ejection station, and indexing head;

FIG. 3A is a side view of the injection station depicted in FIG. 1,particularly illustrating the injection mold die sets, split injectionmold assembly, and resin manifold assembly;

FIG. 3B is a side view of the blowing station depicted in FIG. 1,particularly illustrating the blow mold die sets and split blow moldassembly;

FIG. 3C is a schematic side view of the ejection station depicted inFIG. 1, particularly illustrating the stripper plate used to remove blowmolded articles from the core rods of the indexing head;

FIG. 4 is an isometric view of an injection station configured inaccordance with a first embodiment of the present invention,particularly illustrating the injection station in an open position withtwo die sets attached to a split parison mold assembly comprisingmonolithic neck mold halves and monolithic body mold halves forming aplurality of parison cavities;

FIG. 5 is an isometric view of the injection station of FIG. 4 in aclosed position;

FIG. 6 is an isometric view of the injection station of FIG. 5illustrating a plurality of heat transfer channels in phantom locatedwithin the die sets and the split parison mold assembly;

FIG. 7 is a side view of the injection station depicted in FIG. 5,particularly illustrating the interaction between the heat transferchannels in the die sets and the heat transfer channels in the neck moldhalves and also showing an absence of heat transfer channels in the bodymold halves;

FIG. 8 is a top view of the injection station of FIG. 5 illustrating theheat transfer channels in phantom and includes arrows depicting thedirection of flow of heat transfer fluid through the heat transferchannels from an inlet to an outlet thereof;

FIG. 9 is a cutaway front view of the injection station depicted in FIG.5, particularly illustrating the configuration of the heat transferchannels in the neck molds;

FIG. 10 is a fragmentary cross-sectional view of the heat transferchannels taken along line 10-10 in FIG. 7, including arrows depictingthe direction of flow of heat transfer fluid through the heat transferchannels in the die sets to the heat transfer channels in the neck moldhalves;

FIG. 11 is an isometric view of the upper neck mold half of FIG. 4illustrating the open-sided configuration of the contoured heat transferchannels, as well as the interlock seal recesses formed around thecontoured channels;

FIG. 12 is cross-sectional side view of the injection station takenalong line 12-12 in FIG. 9;

FIG. 13 is a cross-sectional side view of the injection station takenalong line 13-13 in FIG. 9;

FIG. 14 is a fragmentary, cross-sectional, enlarged side view of theneck mold halves as illustrated in FIG. 14, particularly illustratinghow the portion of the heat transfer channel closest to the surface ofthe parison cavity is cooperatively defined by the neck mold halves andinterlock insert halves;

FIG. 15 is a fragmentary, cross-sectional, enlarged front view of one ofthe heat transfer channels in one of the neck mold halves, illustratingrelationships between a neck-forming surface and its correspondingcontoured channel;

FIG. 16 is an isometric view of the injection station of FIG. 5 andillustrates a plurality of mechanical fasteners joining the splitparison mold assembly with the die sets;

FIG. 17 is a side view of the injection station depicted in FIG. 5,particularly illustrating the mechanical fasters joining the interlockinsert halves, neck mold halves, and body mold halves together and tothe first and second die sets, respectively;

FIG. 18 is a cutaway top view of the injection station depicted in FIG.16, particularly illustrating the spacing of the mechanical fastenersextending horizontally through the interlock insert halves, neck moldhalves, and body mold halves;

FIG. 19 is a front view of the injection station depicted in FIG. 16,particularly illustrating the spacing of the mechanical fastenersextending vertically through the first or second die set and portions ofthe split parison mold assembly;

FIG. 20 is an isometric view of an injection station configured inaccordance with a second embodiment of the present invention,particularly illustrating the injection station in an open position withtwo die sets attached to a plurality of first or second individual moldhalves, each individual mold half comprising an individual neck moldhalf and an individual body mold half forming one of the parisoncavities;

FIG. 21 is an isometric view of the injection station of FIG. 20 in aclosed position;

FIG. 22 is a front view of the injection station of FIG. 21,particularly illustrating mechanical fasteners independently attachingeach of the individual mold halves to the first or second die set; and

FIG. 23 is a cross-sectional side view of the injection station of FIG.21, particularly illustrating individual body mold halves and individualinterlock inserts independently attached to the first or second die set.

The drawing figures do not limit the present invention to the specificembodiments disclosed and described herein. The drawings are notnecessarily to scale, emphasis instead being placed upon clearlyillustrating the principles of the invention.

DETAILED DESCRIPTION

The following detailed description of the invention references theaccompanying drawings that illustrate specific embodiments in which theinvention can be practiced. The embodiments are intended to describeaspects of the invention in sufficient detail to enable those skilled inthe art to practice the invention. Other embodiments can be utilized andchanges can be made without departing from the scope of the presentinvention. The following detailed description is, therefore, not to betaken in a limiting sense. The scope of the present invention is definedonly by the appended claims, along with the full scope of equivalents towhich such claims are entitled.

In this description, references to “one embodiment”, “an embodiment”, or“embodiments” mean that the feature or features being referred to areincluded in at least one embodiment of the technology. Separatereferences to “one embodiment”, “an embodiment”, or “embodiments” inthis description do not necessarily refer to the same embodiment and arealso not mutually exclusive unless so stated and/or except as will bereadily apparent to those skilled in the art from the description. Forexample, a feature, structure, act, etc. described in one embodiment mayalso be included in other embodiments, but is not necessarily included.Thus, the present technology can include a variety of combinationsand/or integrations of the embodiments described herein.

An injection blow molding system 30, as illustrated in FIGS. 1-23, isconfigured for injection molding a resin into a plurality of parisonsand blow molding the parisons into a plurality of molded articles. Asillustrated in FIG. 1, the injection blow molding system 30 maycomprise: a resin source 32, a resin feed system 34, a heat transferfluid source 36, a temperature control system 38 comprising at least onetemperature control unit 40, and an injection blow molding (IBM) machine42.

The resin source 32 may be any apparatus for producing and/or storingresin suitable for being molded and hardened into one or more moldedarticles. For example, the resin provided at the resin source 32 may bepolyolefin resin. The resin feed system 34 may be coupled in fluid-flowcommunication with the resin source 32 and configured to inject resininto cavities of a mold of the IBM machine 42, as described below.

The heat transfer fluid source 36 may be any system capable of providingan amount of heat transfer fluid sufficient to supply the heat transferfluid to desired portions of the IBM machine 42 in a desired quantityand for a desired length of time during an injection molding process.For example, the heat transfer fluid source 36 may be a water supply ora supply of any fluid of a sufficient viscosity to freely flowthroughout desired portions of the IBM machine 42. The heat transferfluid may also have sufficient thermal characteristics to remain withina desired temperature range as it flows through the desired portions ofthe IBM machine 42, as described in detail below.

The temperature control system 38 may comprise one or more of thetemperature control units 40 (e.g., thermolators) coupled in fluid-flowcommunication with the heat transfer fluid source 36 and operable tocontrol the temperature of the heat transfer fluid within apredetermined temperature range. In some embodiments, a plurality of thetemperature control systems 38 and/or a plurality of the temperaturecontrol units 40 may be provided. However, in some embodiments, only onetemperature control unit 40 is used to control the temperature of heattransfer fluid injected into the IBM machine 42. The temperature controlunit 40 may provide heat transfer fluid of a substantially uniformtemperature to the desired portions of the IBM machine 42, as describedin detail below.

As illustrated in FIG. 2, the IBM machine 42 may be configured forinjection blow molding a plurality of parisons and/or molded articles.The IBM machine 42 may comprise an indexing head 44, an injectionstation 46, a blowing station 48, and an ejection station 50. Theinjection blow molding process performed with the IBM machine 42 mayinclude inserting polyolefin resin at the injection station 46 to formthe parisons while simultaneously passing a heat transfer fluid throughheat transfer channels defined within the injection station 46 toregulate the temperature of the injection station 46, as describedbelow. The injection blow molding process may then include actuating theindexing head 44 to transfer the resulting parisons from the injectionstation 46 to the blowing station 48 to be blow molded into moldedarticles. Next, the molded articles may be transferred via the indexinghead 44 to the ejection station 50, where the parisons are then ejectedfrom the IBM machine 42. The injection blow molding process describedherein may be performed repetitively by the IBM machine 42. For example,the method steps described herein may be repeated at least 100, 1,000,or 10,000 consecutive times.

The indexing head 44 is configured for transferring the parisons fromthe injection station 46 to the blowing station 48 and then to theejection station 50. The indexing head 44 may comprise a face block 52on one or more outward-facing sides thereof, one or more core rodretainer plates 56 attached to the face blocks 52, and one or more corerods 54 attached to the core rod retainer plates 56. Each of the corerods 54 may be spaced a distance apart from adjacent core rods 54 andmay be shaped according to a desired interior shape of the parisons tobe formed thereon. In one embodiment of the IBM machine 42, the indexinghead 44 may be configured to rotate the core rods 54 from the injectionstation 46 to the blowing station 48 and then to the ejection station 50as directed by an operator or automated control devices (not shown). Forexample, the face blocks 52 may be arranged in a substantiallytriangular configuration with core rods 54 protruding from one or moresides of the triangular configuration, and the indexing head 44 mayrotate approximately 120 degrees to move the core rods 54 on one side ofthe triangular configuration from the injection station 46 to theblowing station 48. In some embodiments of the injection blow moldingsystem 30, the indexing head 44 may have core rods 54 protruding fromeach side, such that the injection station 46, blowing station 48, andejection station 50 may each operate simultaneously on a different setof parisons or molded articles.

The injection station 46 may be configured for injection molding theresin into the parisons. Specifically, the injection blow moldingprocess may comprise injection molding a resin into a plurality ofparisons at the injection station 46. As depicted in FIG. 1, theinjection station may be fluidly coupled with the resin source 32, theresin feed system 34, the heat transfer fluid source 36, and thetemperature control system 38 and/or unit 40. The injection station 46may comprise at least a portion of the resin feed system 34, asillustrated in FIG. 4. For example, the resin feed system 34 maycomprise or be fluidly coupled with an injection manifold 58 and one ormore nozzles 60 positioned and configured for injecting resin into theone or more parison cavities.

Referring again to FIG. 2, the blowing station 48 may be configured forblow molding the parisons into the molded articles and the injectionblow molding process may include the steps of transferring the parisonsfrom the injection station 46 to the blowing station 48 and then blowmolding the parisons formed at the injection station 46 into moldedarticles at the blowing station 48.

As shown in FIG. 3B, the blowing station 48 may comprise an upper dieshoe 62, a lower die shoe 64, an upper mold half 66 coupled to the upperdie shoe 62, and a lower mold half 68 coupled to the lower die shoe 64.The upper die shoe 62 and/or the lower die shoe 64 may be movable towardand away from each other, moving the blowing station 48 between an openposition and a closed position. For example, the upper die shoe 62 andits corresponding upper mold half 66 may move upward and downward on ablowing station guide pin 70 fixed relative to the lower die shoe 64and/or the lower mold half 68.

As shown in FIGS. 2 and 3C, the ejection station 50 may comprise astripper plate 72 or any other device configured for pushing, pulling,dumping, or otherwise stripping the parisons off of the core rods 54once they have been blow molded. For example, once the indexing head 44moves the molded articles from the blowing station 48 to the ejectionstation 50, the stripper plate may be inserted adjacent to a top edge ofthe necks of the molded articles, between the necks and a center pointof the indexing head 44. Then the stripper plate 72 may be movedlaterally away from the center point of the indexing head 44, thusstripping the core rods 54 of the molded articles resting thereon.

In some embodiments of the IBM machine 42 described above, aconventional indexing head 44, blowing station 48, and/or ejectionstation 50 may be used. However, the injection station 46 disclosedherein may comprise a multitude of improvements over prior art injectionstations. Referring now to FIGS. 3 a and 4-7, in various embodiments ofthe IBM machine 42 described herein, the injection station 46 maycomprise first and second die sets 74,76, a split parison mold assembly78 comprising first and second parison mold halves 80,82 coupled to thefirst and second die sets 74,76 respectively, and a plurality of heattransfer channels 84 (dashed lines in FIGS. 6 and 7) defined within thedie sets 74,76 and/or the split parison mold assembly 78 for regulatinga temperature of the parison forming surfaces of the split parison moldassembly 78. The first and second parison mold halves 80,82 may also bereferred to herein as first and second mold half assemblies. When thepair of first and second die sets 74,76 is shifted from an open positionto a closed position, the first and second parison mold halves maycooperatively define one or more parison cavities 86. In someembodiments of the injection station 46, the first and/or second diesets 74,76 may slide along an injection station guide pin 88 whenactuated between the open and closed positions.

The first and second die sets 74,76 (also referred to herein as upperand lower die sets of the injection station 46) may be formed of nickelplate or other die set materials known in the art. The die sets 74,76may be shiftable between the open position and the closed position, asmentioned above. The injection blow molding process may thereforeinclude a step of shifting the first and second die sets 74,76 of theinjection molding station 46 from the open position to the closedposition and from the closed position to the open position. At least oneof the die sets 74,76 may be configured to actuate toward and away fromthe other of the die sets 74,76. For example, the first die set 74 maymove toward and away from the second die set 76 along the injectionstation guide pin 88.

The first and second parison mold halves 80,82 of the split parison moldassembly 78 may be directly coupled to the first and second die sets74,76 respectively. As used herein, the term “directly coupled” denotesconnection of a first component to a second component in a manner suchthat at least a portion of the first and second components physicallycontact one another. The first parison mold half 80 may have a firstparison cavity surface 90 (FIG. 13) and the second parison mold half 82may have a second parison cavity surface 92 (FIG. 13). When the splitparison mold assembly 78 is in the closed position, the first and secondparison cavity surfaces 90,92 may define the one or more parisoncavities 86 within which the resin is received. The resin feed system 34may be coupled in fluid-flow communication with the parison cavities 86and operable to inject the resin into the parison cavities 86.

The injection blow molding process may include injection molding apolyolefin resin into a plurality of parisons at the injection station46. This injection molding process may comprise shifting the splitparison mold assembly 78 from the open position to the closed position,then introducing or injecting the resin, such as polyolefin resin, intothe parison cavities 86 cooperatively defined by the first and secondparison cavity surfaces 90,92 of the split parison mold assembly 78 whenthe split parison mold assembly 78 is in the closed position. The resinfills the parison cavities 86 and may remain therein until it hardens toa point at which it can at least temporarily hold its shape when thesplit parison mold assembly 78 is opened. Then the die sets 74,76 may beshifted from the closed position to the open position and the parisonsmay be removed from the parison mold halves 80,82 while the die sets74,76 are in the open position.

As perhaps best illustrated in FIGS. 13 and 14, each of the parisoncavity surfaces 90,92 may comprise a body-forming surface 94,96 fordefining the exterior shape of the bodies of the parisons and aneck-forming surface 98,100 for defining the exterior shape of the necksof the parisons when the split parison mold 78 is in the closedposition.

In various embodiments of the injection station 46, the split parisonmold assembly 78 may comprise first and second body mold halves 102,104,first and second neck mold halves 106,108, and first and secondinterlock insert halves 110,112 coupled to the first and second die sets74,76 respectively. The neck-forming surfaces 98,100 (FIG. 14) may beformed into the neck mold halves 106,108 and the body-forming surfaces94,96 may be formed into the body mold halves 102,104, respectively.

In some embodiments of the injection station 46, the body mold halves102,104 are each monolithic components having a plurality of the parisonbody-forming surfaces 94,96 formed therein via a molding or millingmanufacturing process. As used herein, the term “monolithic” meansformed of a single body or member; not of multiple bodies or membersfastened together. The monolithic body mold halves 102,104 may beconfigured such that the first body mold half 102 and the second bodymold half 104 cooperatively define the exterior shape of the bodies ofat least two, at least four, or at least six of the parisons. In otherembodiments of the injection station 46, as described below, the bodymold halves 102,104 may each comprise a plurality first body mold halves102 and a plurality of second body mold halves 104 each independentlycoupled to one of the die sets 74,76, with each first body mold half 102and each corresponding second body mold half 104 comprising at least onebody-forming surface 94,96 formed therein.

The first and second neck mold halves 106,108 can be directly coupled tothe first and second die sets 74,76 respectively, and are disposedbetween the first and second body mold halves 102,104 and the first andsecond interlock inserts 110,112 respectively.

In some embodiments of the injection station 46, the neck mold halves106,108 are each monolithic components having a plurality of the parisonneck-forming surfaces 98,100 formed therein via a molding or millingmanufacturing process. The monolithic neck mold halves 106,108 may beconfigured such that the first neck mold half 106 and the second neckmold half 108 cooperatively define the exterior shape of the necks of atleast two, at least four, or at least six of the parisons.

In other embodiments of the injection station 46, as described below,the neck mold halves 106,108 may each comprise a plurality first neckmold halves 106 and a plurality of second neck mold halves 108 eachindependently coupled to one of the die sets 74,76, with each first neckmold half 106 and each corresponding second neck mold half 108comprising at least one neck-forming surface 98,100 formed therein.

The first and second interlock inserts 110,112 (also referred to hereinas interlock insert halves) may be directly coupled to the first andsecond die sets 74,76 respectively, adjacent to the first and secondneck mold halves 106,108. The first and second neck mold halves 106,108may be disposed between the first and second interlock inserts 110,112and the first and second body mold halves 102,104 respectively. Theinterlock insert halves 110,112 along with the first and second neckmold halves 106,108 may cooperatively form at least a portion of theheat transfer channels 84, as later described herein.

The heat transfer channels 84, as illustrated in FIGS. 6-10, are formedin the die sets 74,76 and/the parison mold halves 80,82 and areconfigured to receive the heat transfer fluid. For example, the heattransfer channels 84 may be configured to receive heat transfer fluidfrom the heat transfer fluid source 36 and pass the heat transfer fluidfrom heat transfer channels 84 defined within the first and second diesets 74,76 into heat transfer channels 84 defined within the first andsecond parison mold halves 80,82 respectively. Heat transfer fluid maybe passed through the plurality of heat transfer channels 84 definedwithin the injection station 46 to regulate the temperature of at leasta portion of the parison cavity surfaces 90,92.

The heat transfer channels 84 may be coupled in fluid-flow communicationwith the heat transfer fluid source 36 and the temperature controlsystem 38. The temperature control system 38 may thus control thetemperature of the heat transfer fluid fed into the heat transferchannels 84. In some embodiments of the injection blow molding system30, there may be one or more temperature control systems 38 ortemperature control units 40, but only one of the temperature controlunits 40 may be associated with the injection station 46 and its heattransfer channels 84. The injection molding process described herein maytherefore further comprise passing the heat transfer fluid from a singletemperature control unit 40 through all the heat transfer channels 84defined within the injection station 46. In some embodiments of theinjection blow molding system 30, all of the heat transfer fluid passedthrough the heat transfer channels 84 enters the injection station 46 atsubstantially the same temperature.

The injection station 46 may define one or more inlets 114,116 forreceiving the heat transfer fluid from the temperature control unit 40and one or more outlets 118,120 for allowing fluid to flow out of theheat transfer channels. In some embodiments of the injection blowmolding system 30, the injection station 46 may define no more than twoinlets 114,116 for receiving the heat transfer fluid from thetemperature control unit 40 the heat transfer fluid from the temperaturecontrol unit 40 into the heat transfer channels 84. For example, each ofthe first and second die sets 74,76 may comprise only one inlet 114,116,respectively, for receiving fluid to be passed through all of the heattransfer channels 84 defined with that die set and associated parisonmold half.

As noted above, at least a portion of the heat transfer channels 84 maybe defined within the first and second die sets 74,76. Furthermore, atleast a portion of the heat transfer channels 84 may be defined withinthe first and second parison mold halves 80,82. For example, at least aportion of the heat transfer channels 84 may be defined within the firstand second neck mold halves 106,108 of the first and second parison moldhalves 80,82. The heat transfer channels 84 defined within the first andsecond parison mold halves 80,82 may be connected in fluid-flowcommunication with at least a portion of the heat transfer fluidchannels 84 defined within the first and second die sets 74,76. Forexample, heat transfer fluid can be supplied to heat transfer channels84 defined within the first and second parison mold halves 80,82 by heattransfer channels 84 defined within the first and second die sets 74,76respectively.

As perhaps best illustrated in FIG. 8, all of the heat transfer channels84 defined within the first die set 74 may be connected in serialfluid-flow communication, and all of the heat transfer channels 84defined within the second die set 76 may be connected in serialfluid-flow communication. As used herein, “serial fluid-flowcommunication” denotes the connection of multiple fluid carrying bodiesor channels in a manner such that fluid flows sequentially through themultiple bodies or channels. The heat transfer channels 84 definedwithin each of the first and second die sets 74,76 may comprise aplurality of spaced-apart, substantially linear channels 122. In someembodiments of the injection station 46, each of the die sets maycomprise a minimum of 2, 3, or 4 of the linear channels 122 and amaximum of 40, 20, or 8 of the linear channels 122. Each of the linearchannels 122 may have a length of at least 6, 12, or 16 inches and/ornot more than 60, 48, or 36 inches. Furthermore, the linear channels 122may extend substantially parallel to one another. The average lateralspacing between adjacent ones of the linear channels 122 may be at least0.5, 0.75, 1.0, or 1.25 inches and/or not more than 8, 6, 4, or 2inches. Furthermore, the average diameter of the linear channels 122 inthe die sets 74,76 may be at least 0.05, 0.15, or 0.25 inches and/or notmore than 3.0, 1.5, or 0.75 inches.

As mentioned above, the linear channels 122 may be coupled in serialfluid-flow communication with one another. For example, one or morecrossing heat transfer channels 124 may be positioned proximate one ormore ends of the linear channels 122 and may provide fluid communicationbetween adjacent ones of the linear channels 122. For example, thelinear channels 122 and the crossing channels 124 may cooperativelydefine heat transfer channels that snake back and forth laterally acrosseach of the die sets 74,76. For example, the heat transfer fluid maytravel in a first direction through a first one of the linear channels122, enter a first one of the crossing channels 124 or a first portionof one of the crossing channels 124, and then flow in a second, oppositedirection through a second one of the linear channels 122. In someembodiments of the injection station 46, plugs 126 may be strategicallyplaced throughout the linear channels 122 and/or the crossing channels124, thereby directing the flow of the heat transfer fluid, asillustrated in FIG. 8. Furthermore, the plugs 126 may also be placed ator into each end of the linear and crossing channels 122,124 to preventheat transfer fluid from entering or exiting at any locations other thanthe inlets 114,116 and outlets 118,120.

At least a portion of the heat transfer channels 84 defined within thedie sets 74,76 connect the heat transfer channels 84 defined within theparison mold halves 80,82 in serial fluid-flow communication with oneanother. As illustrated in FIG. 10, the parison mold halves 80,82 mayeach define at least two spaced-apart heat transfer channels, referredto herein as mold half channels 128. The mold half channels 128 may beformed in the body mold halves 102,104 and/or the neck mold halves106,108, as later described herein. Specifically, the first and seconddie sets 74,76 may each comprise at least one connecting heat transferchannel or one connecting portion of one of the linear channels thatprovides fluid communication between the mold half channels 128. Forexample, the mold half channels 128 may each have an inlet end 130 andan outlet end 132 in fluid communication with at least one of the linearchannels 122 in the die sets. The linear channel 122 may have one of theplugs 126 placed therein between the inlet end 130 and the outlet end132 of one of the mold half channels 128 to redirect the heat transferfluid into that mold half channel 128. The space between adjacent onesof the plugs 126 within the linear channels 122 in fluid communicationwith the mold half channels 128 may be referred to herein as aconnecting portion or a connecting heat transfer channel 134, because itfluidly connects the outlet end 130 of one mold half channel 128 withthe inlet end 132 of another mold half channel 128, as illustrated inFIG. 10.

The inlet end 130 and the outlet end 132 of the mold half channels 128may each be fluidly connected with the at least one of the linearchannels 122 via extension channels 136. In some embodiments of theinjection station 46, the extension channels 136 may extend downwardfrom and substantially perpendicular to at least one of the linearchannels 122.

In some embodiments of the injection station 46, the total volume of theheat transfer channels 84 may be at least 10, 20, or 40 cubic inchesand/or not more than 500, 250, or 100 cubic inches. Additionally, thetotal volume of the heat transfer channels 84 defined within the firstand second die sets 74,76 may be at least 5, 15 or 30 cubic inchesand/or not more than 400, 200, or 80 cubic inches. The total volume ofthe heat transfer channels 84 defined within the first and secondparison mold halves 80,82 may be at least 1, 3, or 5 cubic inches and/ornot more than 100, 50, or 20 cubic inches. The total volume of the heattransfer channels 84 defined within the first and second body moldhalves 102,104 may be less than 30, 15, or 5 cubic inches, and the totalvolume of the heat transfer channels 84 defined within the first andsecond neck mold halves 106,108 may be at least 1, 3, or 5 cubic inchesand/or not more than 100, 50, or 20 cubic inches.

The ratio of the total volume of the heat transfer channels 84 definedwithin the die sets 74,76 to the total volume of heat transfer channels84 defined in the split parison mold assembly 78 may be at least 1:1,2.5:1, or 3.5:1 and/or not more than 20:1, 12:1, or 8:1. The ratio ofthe total volume of the heat transfer channels 84 defined within the diesets 74,76 to the total volume of heat transfer channels 84 defined inthe body mold halves 102,104 may be at least 1:1. Thus, less than 50,30, 25, 15, or 10 percent of the total volume of the heat transferchannels 84 in the injection station 46 may be defined within the bodymold halves 102,104. For example, in some embodiments of the injectionstation 46 none of the heat transfer channels 84 are defined within thebody mold halves 102,104. In various embodiments of the injectionstation 46, at least 50, 60, or 70 percent of the total volume of theheat transfer channels 84 is located in heat transfer channels that arespaced more than 1, 3, or 5 inches from the parison cavity surfaces90,92.

In some embodiments of the injection station 46, at least 20, 30, 50, or70 percent and/or not more than 98, 95, or 90 percent of the totalvolume of the heat transfer channels 84 is defined within the die sets74,76. In some embodiments of the injection station 46, at least 2, 5,or 10 percent and/or not more than 80, 50, or 30 percent of the totalvolume of the heat transfer channels 84 is defined within the splitparison mold assembly 78. In some embodiments of the injection station46, at least 2, 5, or 10 percent and/or not more than 80, 50, or 30percent of the total volume of the heat transfer channels 84 may bedefined within the neck mold halves 106,108.

It may be desirable for the body-forming surfaces 94,96 of the parisonmolds 80,82 to stay within target temperature ranges during theinjection molding process. In some embodiments of the injection station46, the target surface temperature of the body-forming surfaces (i.e.,the target body surface temperature) may be at least 190, 200, or 205°F. and/or not more than 230, 220, or 215° F.

During the injection molding, while the resin is received in the parisoncavities 86, the surface temperature of at least 70, 80, or 90 percentof the total surface area of the body-forming surfaces 94,96 of thesplit parison mold assembly 78 may be maintained at or within 20, 10, or5° F. of the target body surface temperature. For example, a target bodysurface temperature may be 210° F., and during the injection molding,the temperature of at least 90 percent of the total surface area of thebody-forming surfaces 94,96 may be maintained between 205 and 215° F.

During the injection molding, the temperature of at least 70, 80, or 90percent of the total surface area of the neck-forming surfaces 98,100may be maintained within 20, 10, or 5° F. of a target neck surfacetemperature. For example, the temperature of at least 70, 80, or 90percent of the total surface area of the neck-forming surfaces 98,100may be maintained within a range having a minimum of 50 or 75° F. and amaximum of 150 or 175° F. In some embodiments of the injection station46, the target neck surface temperature may be at least 10, 25, or 50°F. less than the target body surface temperature. For example, if thetarget neck surface temperature is in the range of 50 to 175° F. thenthe target body surface temperature may be in the range of 190 to 230°F. In one example embodiment of the injection station 46, the targetbody surface temperature may be 210° F., and the target neck surfacetemperature may be at least 25° F. less than the target body surfacetemperature.

In some embodiments of the injection station 46, at least 75, 90, or 100volume percent of the heat transfer fluid introduced into the heattransfer channels 84 is introduced at an inlet temperature that is at orwithin 20, 10, or 5° F. of a target inlet temperature. The target inlettemperature may be at least 40, 50, or 60° F. and/or not more than 150,100, or 90° F. The temperature of the heat transfer fluid may becontrolled in a single temperature control unit 40 (e.g., thermolator)prior to introducing the heat transfer fluid into the heat transferchannels 84.

In certain embodiments, the neck mold halves 106,108 may be coupled tothe die sets 74,76 independently of the body mold halves 102,104. Afirst insulating gap 138 may be defined between at least a portion ofthe first body mold half 102 and the first neck mold half 106, and asecond insulating gap 140 may be defined between at least a portion ofthe second body mold half 104 and the second neck mold half 108.

As noted above, at least a portion of the heat transfer channels 84 maybe defined within the first and second neck mold halves 106,108. Forexample, at least some of the spaced-apart heat transfer channels ormold half channels 128 may be partially or entirely defined within thefirst and second neck mold halves 106,108. In some embodiments of theinjection station 46, at least a portion of the heat transfer channels84 defined within the first and second neck mold halves 106,108 may bespaced at least 0.05, 0.1, or 0.15 inches and/or not more than 2, 1, or0.5 inches from the neck-forming surfaces 98,100. In some embodiments ofthe injection station 46, all of the heat transfer channels 84 that arespaced less than 1 inch from the first and second parison cavitysurfaces 90,92 are defined within the neck mold halves 106,108.

The heat transfer channels 84 defined in the first and second neck moldhalves 106,108 may include a plurality of contoured channels 142associated with the neck-forming surfaces 98,100. As perhaps best shownin FIG. 15, the curvature of the contoured channels 142 maysubstantially correspond to the curvature of the necks of the parisonsto be formed at the injection station 46. Specifically, the contouredheat transfer channels 142 may include an inner face 144 having a shapethat substantially corresponds to the shape of the neck-forming surface98,100 with which it is associated.

As illustrated in FIGS. 14 and 15, the curvature of each of thecontoured heat transfer channels 142 may be substantially concentricwith the curvature of the neck of the parison with which it isassociated and the neck-forming surface 98,100 with which it isassociated. The inner face 144 of the contoured heat transfer channel142 may have an arcuate shape. The inner face 144 of the contoured heattransfer channel 142 may also be spaced from the neck-forming surface98,100 with which it is associated by a distance S (as illustrated inFIG. 15), which may be at least 0.05, 0.1, or 0.15 inches and/or notmore than 2, 1, or 0.5 inches. The inner face 144 of the contoured heattransfer channel 142 may have a radius of curvature r₁ that is at least0.25, 0.5, 0.75, or 1 inch and/or not more than 5, 3, or 2. Furthermore,the inner face 144 of the contoured heat transfer channel 142 may extendthrough an angle θ (as illustrated in FIG. 15) that is at least 90, 120,or 140 degrees and/or not more than 175 or 180 degrees. The radius ofthe neck-forming surface 98,100 is denoted by r₂ in FIG. 15. The lengthof each of the contoured channels 142 may be at least 1, 1.25, or 1.5inches and/or not more than 10, 8, or 5 inches.

At least one of the contoured channels 142 may be located between andfluidly connected to a supply channel 146 and a return channel 148, withthe supply channel 146 extending to the inlet end 130 and the returnchannel 148 extending to the outlet end 132 of the mold half channels128. The supply and return channels 146,148 may extend from thecontoured heat transfer channel 142 in a direction that is generallyaway from the neck-forming surface 98,100 with which the contoured heattransfer channel 142 is associated. The supply and return channels146,148 may be substantially linear and/or parallel with each other andconnected to generally opposite ends of the contoured heat transferchannel 142. The supply and return channels 146,148 may also besubstantially perpendicular relative to the linear channels 122 in thedie sets 74,76.

In some embodiments of the injection station 46, the first and secondinterlock inserts 110,112 may be disposed adjacent the first and secondneck mold halves 106,108 respectively, such that at least a portion ofthe contoured channels 142 are cooperatively defined by the interlockinserts 110,112 and the neck mold halves 106,108, as illustrated inFIGS. 13-14. For example, the contoured channels 142 may be milled intoa front face of the neck mold halves 106,108, and then the first andsecond interlock inserts 110,112 may be attached to the front face ofthe first and second neck mold halves 106,108 respectively, therebycooperatively forming the contoured channels 142.

An interlock seal 150 may be placed around a periphery of each of thecontoured channels 142 at the front face of the neck mold halves106,108, such that the interlock seal 150 is disposed between the neckmold halves 106,108 and their corresponding interlock inserts 110,112.The interlock seal 150 may be a gasket, sealant, or any other sealingdevice configured to prevent heat transfer fluid from leaking betweenthe front face of the neck mold halves 106,108 and the interlock inserts110,112.

As shown in FIG. 9, the injection station 46 may further comprise aplurality of first and second sealing members 152,154. The first andsecond sealing members may be gaskets, sealant, or any other sealingdevice configured to prevent heat transfer fluid from leaking betweenthe inlet ends 130 and outlet ends 132 of the mold half channels 128 andthe extension channels 136 fluidly connecting the linear channels 122with the mold half channels 128. Each of the first sealing members 152may be disposed between the first die set 74 and the first parison moldhalf 80 proximate a location where one of the heat transfer channels 84of the first die set 74 connects in fluid-flow communication with one ofthe heat transfer channels 84 in the first parison mold half 80. Each ofthe second sealing members 154 may be disposed between the second dieset 76 and the second parison mold half 82 proximate a location whereone of the heat transfer channels 84 in the second die set 76 connectsin fluid-flow communication with one of the heat transfer channels 84defined in the second parison mold half 82.

Each component of the split parison mold assembly 78 may be directlyattached to its corresponding die set 74,76. In some embodiments of theinjection station 46, various components may be independently attachedto the die sets 74,76. Specifically, the first and second body moldhalves 102,104, first and second neck mold halves 106,108, and first andsecond interlock insert halves 110,112 may each be directly andindependently coupled to the first or second die sets 74,76,respectively. Therefore, the body mold halves 102,104, neck mold halves106,108, and interlock insert halves 110,112 may each be independentlydisconnected from the die sets 74,76 without removing any of the othercomponents.

As illustrated in FIGS. 16-19, a plurality of male threaded members maycouple the first and second interlock inserts, neck mold halves, andbody mold halves to one another and/or to the first and second die sets,respectively. For example, the first and second monolithic neck moldhalves may be directly coupled to the first and second die setsrespectively, and the first and second body mold halves may be directlycoupled to the first and second die sets respectively. The coupling ofthese components may be accomplished using a plurality of mechanicalfasteners 156.

For example, in the embodiments illustrated in FIGS. 16-19, themechanical fasteners 156 comprise a plurality of vertically-extendingmale threaded members extending through the first and second die sets74,76 and into either one of the interlock insert halves 110,112 or oneof the body mold halves 102,104. In FIGS. 16-19, the mechanicalfasteners 156 also include a plurality of horizontally-extending malethreaded members extending through the first or second interlock inserthalves 110,112, then through the first or second neck mold halves106,108, respectively, and into the first or second body mold halves102,104 respectively.

FIGS. 4-19 illustrate an injection station 46 with the first and asecond parison mold halves 80,82, each comprising one monolithic bodymold half, one monolithic neck mold half, and one monolithicinterlocking insert half. However, in alternative embodimentsillustrated in FIGS. 20-23, a plurality of first individual mold halves158 and a plurality of second individual mold halves 160 are eachindependently attached to their respective die sets 74,76 in aspaced-apart configuration. As used herein, the term “independentlycoupled” denotes connection of a first component to a second componentin a manner such that disconnection and removal of the first componentfrom the second component does not require disconnection of anyfasteners other than the fasteners that contact and connect both thefirst or second components.

In this configuration, each of the first individual mold halves 158 hasa corresponding one of the second individual mold halves 160 with whichit cooperates to define a single one of the parison cavities 86. Incertain embodiments, each of the first individual mold halves 158 arehorizontally-spaced from one another to thereby form first gaps 174therebetween, and each of the second individual mold halves 160 arehorizontally-spaced from one another to thereby form second gaps 176therebetween.

Advantageously, no horizontally-extending fasteners are used or requiredto couple the first individual mold halves 158 to one another or tocouple the second individual mold halves 160 to one another, since theyare each independently attached to their respective die sets 74,76.Specifically, each of the first individual mold halves 158 may becoupled to the first die set 74 by one or more vertically-extendingmounting fasteners 156, and each of the second individual mold halves160 may be coupled to the second die set 76 by one or morevertically-extending mounting fasteners 156. The vertically-extendingmounting fasteners may each include a male threaded portion. In thisembodiment of the injection station 46, vertically-extending mountingfasteners may be the only means used to couple the first and secondindividual mold halves 158,160 to the first and second die sets 74,76,respectively.

The plurality of first and second mold halves 158,160 may each comprisea first and second individual body mold half 162,164, a first and secondindividual neck mold half 166,168, and a first and second individualinterlocking insert half 170,172 respectively. Specifically, the firstand second body mold halves 102,104 may each comprise a plurality offirst and second individual body mold halves 162,164, each directly andindependently coupled to the first or second die set 74,76 respectivelyand each configured to define at least a portion of the exterior shapeof the body of only one of the parisons. Furthermore, the first andsecond neck mold halves 106,108 may each comprise a plurality of firstand second individual neck mold halves 166,168, each directly andindependently coupled to the first or second die set 74,76 respectivelyand each configured to define at least a portion of the exterior shapeof the neck of only one of the parisons. Also, the first and secondinterlocking insert halves 110,112 may each comprise a plurality offirst and second individual interlocking insert halves 170,172 eachdirectly and independently coupled to the first or second die set 74,76respectively. The individual body mold halves 162,164 may each be spacedapart from one another, the individual neck mold halves 166,168 may eachbe spaced apart from one another, and/or the individual interlockinginsert halves 170,172 may each be spaced apart from one another.

Each of the first individual body mold halves 162 may have acorresponding second individual body mold half 164, and each of thefirst individual neck mold halves 166 may have a corresponding secondneck mold half 168. Each pair of corresponding first and secondindividual body mold halves 162,164 may cooperatively defines theexterior shape of the body of one of the parisons, and each pair ofcorresponding first and second individual neck mold halves 166,168 maycooperatively define the exterior shape of the neck of one of theparisons. In some embodiments, the split parison mold of the injectionstation 46 may comprise at least two, four, or six of the firstindividual body mold halves 162,164 and at least two, four, or six ofthe second individual body mold halves 166,168.

The individual first and second neck mold halves 166,168 may each haveone of the mold half channels 128 formed therein and in fluid-flowcommunication with the heat transfer channels 84 in the first or seconddie set 74,76. For example, heat transfer fluid may flow from a firstmold half channel in one individual first neck mold half to a secondmold half channel in an adjacent individual first neck mold half via aconnecting portion of one of the linear channels 122 or via one of theconnecting heat transfer channels 134 in the first die set 74.

The injection molding process performed with the injection station 46embodiment illustrated in FIGS. 20-23 is identical to the processperformed with embodiments having primarily monolithic components, as inFIGS. 4-19. For example, the injection molding process may comprisemoving the split parison mold assembly 78 from the open to the closedposition, with the core rods 54 disposed within the parison cavities 86,then injecting resin into the plurality of parison cavities 86.Simultaneously, the heat transfer fluid may be passed through the heattransfer channels 84 throughout the injection station 46.

In some alternative embodiments of the injection station 46, at leastsome components of the first and second parison mold halves 80,82 may bemonolithic while other components are comprised of a plurality ofindividual components. For example, the first and second body moldhalves 102,104 may each be monolithic components while the first andsecond neck mold halves 106,108 may comprise a plurality of firstindividual neck mold halves 166 and a plurality of second individualneck mold halves 168.

In split parison mold configurations described above where at least someof the components of the split parison mold assembly 78 areindependently coupled with the die sets 74,76 and are not directlycoupled with each other, the IBM machine 42 may be reconfigured toproduce different shapes and sizes of parisons and/or molded articles.For example, in an injection blow molding process, a first group ofparisons may be injection molded at the injection station 46 using afirst split parison mold assembly to define the exterior shape of thefirst group of parisons. The first group of parisons may then be blowmolded into a first group of molded articles at the blowing station 48.Next, at least one component of the first split parison mold assemblymay be replaced with another component, thus creating a second splitparison mold assembly attached to the die sets. Then a second group ofparisons may be injection molded at the injection station 46 using thesecond split parison mold assembly to define the exterior shape of thesecond group of parisons. The second group of parisons may then be blowmolded into a second group of molded articles at the blowing station 48.The first and second groups of parisons may have different exteriorshapes.

In some embodiments, the same blowing station 48 may be used to blowmold both the first and second groups of parisons into the first andsecond groups of molded articles respectively. Alternatively, the stepof blow molding the first group of parisons may utilize a first blowmold assembly, such as a first upper mold half and a first lower moldhalf, to define the external shape of the first group of moldedarticles. Then the injection blow molding process may further comprisereplacing the first blow mold assembly or the first upper and lower moldhalves, with a second blow mold assembly, such as a second upper moldhalf and a second lower mold half. The second blow mold assembly mayhave a substantially different configuration than the first blow moldassembly. The step of blow molding the second group of parisons may thusutilize the second blow mold assembly, or second upper and lower moldhalves, to define the external shape of the second group of moldedarticles. The first and second groups of molded articles havesubstantially different configurations.

As described above, the injection molding of the first and second groupsof parisons may include passing heat transfer fluid through the heattransfer channels 84 defined within the injection station 46. Thetemperature of the heat transfer fluid introduced into the injectionstation 46 may be substantially the same during the injection molding ofthe first group of parisons and the second group of parisons.

This method of exchanging components of the split parison mold assembly78 may be particularly useful in an initial design of the split parisonmold and/or the blowing station 48. For example, if the first group ofmolded articles exhibits at least one undesirable characteristic, thesecond parison mold assembly may be configured to eliminate theundesirable characteristic in the second group of molded articles. Thenthe second parson mold assembly may replace the first parison moldassembly on the die sets 74,76. The undesirable characteristic mayinclude excessive wall thickness, inadequate wall thickness, and/ornon-uniform wall thickness.

The exchangeable first and second parison mold assemblies may presentrespective first and second parison neck-forming surfaces for definingthe external shape of the necks of the parisons in the first and secondgroups of parisons respectively. Furthermore, the first and secondparison mold assemblies may present respective first and second parisonbody-forming surfaces for defining the external shape of the bodies ofthe parisons in the first and second groups of parisons respectively.

During the injection molding of each of the first and second groups ofparisons, the surface temperature of at least 70 percent of the totalsurface area of the first and second parison body-forming surfaces ismaintain at a temperature within 20° F. of the target body surfacetemperature. For example, the target body surface temperature may be210° F., or may be in any of the ranges disclosed herein for the targetbody surface temperature. In one embodiment, during the injectionmolding of each of the first and second groups of parisons, the surfacetemperature of at least 90 percent of the total surface area of thefirst and second parison body-forming surfaces may be maintained in therange of 205 to 215° F. Furthermore, during the injection molding ofeach of the first and second groups of parisons, the temperature of atleast 90 percent of the total surface area of the parison neck-formingsurfaces may be maintained between 75 and 150° F. Although the inventionhas been described with reference to the preferred embodimentillustrated in the attached drawing figures, it is noted thatequivalents may be employed and substitutions made herein withoutdeparting from the scope of the invention as recited in the claims.

1. An injection blow molding system for injection molding a resin into aplurality of parisons and blow molding said parisons into a plurality ofmolded articles, said injection blow molding system comprising: aninjection station for injection molding said resin into said parisons; ablowing station for blow molding said parisons into said moldedarticles; an indexing head for transferring said parisons from saidinjection station to said blowing station; and a heat transfer fluidsource, wherein said injection station defines one or more heat transferchannels coupled in fluid-flow communication with said heat transferfluid source, wherein said injection station further comprises a splitparison mold assembly shiftable between an open position and a closedposition, wherein said split parison mold assembly comprises first andsecond body mold halves for defining the exterior shape of the bodies ofsaid parisons, wherein less than 50 percent of the total volume of saidheat transfer channels is defined within said body mold halves.
 2. Thesystem of claim 1, wherein less than 25 percent of the total volume ofsaid heat transfer channels is defined within said body mold halves,wherein the total volume of said heat transfer channels is at least 10cubic inches.
 3. The system of claim 1, wherein less than 10 percent ofthe total volume of said heat transfer channels is defined within saidbody mold halves, wherein the total volume of said heat transferchannels is in the range of 20 to 250 cubic inches.
 4. The system ofclaim 1, wherein said injection station further comprises first andsecond die sets to which said first and second body mold halves arecoupled respectively, wherein at least 50 percent of the total volume ofsaid heat transfer channels is defined within said die sets, whereinless than 25 percent of the total volume of said heat transfer channelsis defined within said body mold halves, wherein the total volume ofsaid heat transfer channels is in the range of 20 to 250 cubic inches.5. The system of claim 1, wherein said split parison mold assemblyfurther comprises first and second neck mold halves for defining theexterior shape of the necks of said parisons.
 6. The system of claim 5,wherein at least 2 percent of the total volume of said heat transferchannels is defined within said neck mold halves.
 7. The system of claim5, wherein said injection station further comprises first and second diesets to which said first and second neck mold halves are coupledrespectively.
 8. The system of claim 7, wherein said first and secondneck mold halves are directly coupled to said first and second die setsrespectively.
 9. The system of claim 7, wherein each of said first andsecond neck mold halves defines at least two spaced-apart heat transferchannels, wherein each of said first and second die sets comprises atleast one connecting heat transfer channel that provides fluid-flowcommunication between said space-apart heat transfer channels of saidneck mold halves.
 10. The system of claim 5, wherein said heat transferchannels include a plurality of contoured channels at least partlydefined within said first and second neck mold halves, wherein thecurvature of said contoured channels substantially corresponds to thecurvature of the necks of said parisons.
 11. The system of claim 1,wherein said split parison mold further comprises first and second neckmold halves for defining the exterior shape of the necks of saidparisons, wherein at least 50 percent of the total volume of said heattransfer channels is defined within said die sets, wherein at least 5percent of the total volume of said heat transfer channels is definedwithin said neck mold halves, wherein less than 25 percent of the totalvolume of said heat transfer channels is defined within said body moldhalves, wherein the total volume of said heat transfer channels is atleast 20 cubic inches.
 12. An injection blow molding system forinjection molding a resin into a plurality of parisons and blow moldingsaid parisons into a plurality of molded articles, said injection blowmolding system comprising: an injection station for injection moldingsaid resin into said parisons; a blowing station for blow molding saidparisons into said molded articles; an indexing head for transferringsaid parisons from said injection station to said blowing station; and aheat transfer fluid source, wherein said injection station defines oneor more heat transfer channels coupled in fluid-flow communication withsaid heat transfer fluid source, wherein said injection stationcomprises first and second die sets shiftable between an open positionand a closed position, wherein said injection station further comprisesa split parison mold assembly coupled to said first and second die sets,wherein said split parison mold assembly defines a plurality of parisoncavities for receiving said resin when said die sets are in said closedposition, wherein at least a portion of said heat transfer channels aredefined within said first and second die sets.
 13. The system of claim12, wherein at least 20 percent of the total volume of said heattransfer channels is defined within said die sets, wherein the totalvolume of said heat transfer channels is at least 10 cubic inches. 14.The system of claim 12, wherein the ratio of the total volume of saidheat transfer channels defined within said die sets to the total volumeof said heat transfer channels defined within said split parison moldassembly is at least 1:1.
 15. The system of claim 14, wherein the totalvolume of said heat transfer channels is in the range of 20 to 250 cubicinches.
 16. The system of claim 12, wherein in the range of 50 to 95percent of the total volume of said heat transfer channels is definedwithin said die sets, wherein in the range of 5 to 50 percent of thetotal volume of said heat transfer channels is defined within said splitparison mold assembly, wherein the total volume of said heat transferchannels is at least 20 cubic inches.
 17. The system of claim 12,wherein each of said first and second die sets comprises only one inletfor receiving fluid to be passed through all of said heat transferchannels defined with that die set.
 18. The system of claim 12, whereinall of said heat transfer channels defined within said first die set areconnected in serial fluid-flow communication, wherein all of said heattransfer channels defined within said second die set are connected inserial fluid-flow communication.
 19. The system of claim 12, whereinsaid heat transfer channels defined within each of said first and seconddie sets comprise a plurality of spaced-apart, substantially linearchannels.
 20. The system of claim 19, wherein each of said die setscomprises 3 to 20 of said spaced-apart, substantially linear channels,wherein each of said spaced-apart, substantially linear channels has alength of at least 12 inches, wherein said spaced-apart, substantiallylinear channels extend substantially parallel to one another.
 21. Thesystem of claim 12, wherein said split parison mold assembly comprisesfirst and second mold half assemblies coupled to said first and seconddie sets respectively, wherein said mold half assemblies each define atleast two spaced-apart heat transfer channels, wherein said first anddie sets each comprise at least one connecting heat transfer channelthat provides fluid communication between said space-apart heat transferchannels of said mold half assemblies.
 22. The system of claim 12,wherein said split parison mold assembly comprises first and second moldhalf assemblies coupled to said first and second die sets respectively,wherein said first and second mold half assemblies comprise respectivefirst and second body mold halves for defining the exterior shape of thebodies of said parisons, wherein less than 50 percent of the totalvolume of said heat transfer channels is defined within said body moldhalves.
 23. The system of claim 12, wherein said split parison moldassembly comprises first and second mold half assemblies coupled to saidfirst and second die sets respectively, wherein said first and secondmold half assemblies comprise respective first and second neck moldhalves for defining the exterior shape of the necks of said parisons,wherein said first and second neck mold halves are directly coupled tosaid first and second dies sets respectively.
 24. The system of claim12, wherein said split parison mold assembly comprises first and secondmold half assemblies coupled to said first and second die setsrespectively, wherein said first and second mold half assembliescomprise respective first and second body mold halves for defining theexterior shape of the bodies of said parisons, wherein said first andsecond mold half assemblies comprise respective first and second neckmold halves for defining the external shape of the necks of saidparisons, wherein in the range of 50 to 95 percent of the total volumeof said heat transfer channels is defined within said die sets, whereinin the range of 5 to 50 percent of the total volume of said heattransfer channels is defined within said neck mold halves, wherein lessthan 25 percent of the total volume of said heat transfer channels isdefined within said body mold halves, wherein the total volume of saidheat transfer channels is at least 20 cubic inches.
 25. An injectionblow molding system for injection molding a resin into a plurality ofparisons and blow molding said parisons into a plurality of moldedarticles, said injection blow molding system comprising: an injectionstation defining one or more heat transfer channels; and a heat transferfluid source coupled in fluid-flow communication with said heat transferchannels, wherein said injection station comprises first and second diesets shiftable between an open position and a closed position, whereinsaid injection station further comprises first and second mold halfassemblies coupled to said first and second die sets respectively,wherein said first and second mold half assemblies present respectivefirst and second parison cavity surfaces that cooperatively define aplurality of parison cavities when said die sets are in said closedposition, wherein at least 50 percent of the total volume of said heattransfer channels is located in heat transfer channels that are spacedmore than 1 inch from said parison cavity surfaces.
 26. The system ofclaim 25, wherein at least 60 percent of the total volume of said heattransfer channels is located in heat transfer channels that are spacedmore than 1.25 inches away from said parison cavity surfaces.
 27. Thesystem of claim 25, wherein at least 70 percent of the total volume ofsaid heat transfer channels is located in heat transfer channels thatare spaced more than 1.5 inches away from said parison cavity surfaces,wherein the total volume of said heat transfer channels is at least 20cubic inches.
 28. The system of claim 25, wherein the ratio of the totalvolume of said heat transfer channels defined within said die sets tothe total volume of said heat transfer channels defined within said moldhalf assemblies is at least 1:1.
 29. The system of claim 25, whereinsaid first and second mold half assemblies comprise respective first andsecond body mold halves for defining the exterior shape of the bodies ofsaid parisons, wherein less than 50 percent of the total volume of saidheat transfer channels is defined within said body mold halves.
 30. Thesystem of claim 25, wherein said first and second mold half assembliescomprise respective first and second body mold halves for defining theexterior shape of the bodies of said parisons, wherein said first andsecond mold half assemblies comprise respective first and second neckmold halves for defining the exterior shape of the necks of saidparisons, wherein in the range of 50 to 95 percent of the total volumeof said heat transfer channels is defined within said die sets, whereinin the range of 5 to 50 percent of the total volume of said heattransfer channels is defined within said neck mold halves, wherein lessthan 25 percent of the total volume of said heat transfer channels isdefined within said body mold halves, wherein the total volume of saidheat transfer channels is at least 20 cubic inches.
 31. The system ofclaim 25, wherein said injection blow molding system further comprises ablowing station for blow molding said parisons into molded articles andan indexing head for transferring said parisons from said injectionstation to said blowing station.
 32. An injection blow molding processcomprising: (a) injection molding a resin into a plurality of parisonsat an injection station, wherein said injection molding includes— (i)shifting a split parison mold assembly from an open position to a closedposition, (ii) injecting said resin into a plurality of parison cavitiescooperatively defined by parison cavity surfaces of said split parisonmold assembly when said split parison mold assembly is in said closedposition, (iii) passing a heat transfer fluid through heat transferchannels defined within said injection station, wherein at least 50percent of the total volume of said heat transfer channels is spacedmore than 1 inch away from said parison cavity surfaces; (b)transferring said parisons from said injection station to a blowingstation; and (c) blow molding said parisons into molded articles at saidblowing station.
 33. The process of claim 32, wherein at least 60percent of the total volume of said heat transfer channels is spacedmore than 1.25 inches away from said parison cavity surfaces, whereinthe total volume of said heat transfer channels is at least 10 cubicinches.
 34. The process of claim 32, wherein at least 70 percent of thetotal volume of said heat transfer channels is spaced more than 1.5inches away from said parison cavity surfaces, wherein the total volumeof said heat transfer channels is at least 20 cubic inches.
 35. Theprocess of claim 32, wherein said injection station comprises first andsecond die sets to which said split parison mold assembly is coupled,wherein at least 50 percent of the total volume of said heat transferchannels is defined within said first and second die sets, wherein thetotal volume of said heat transfer channels is at least 20 cubic inches.36. The process of claim 35, wherein said passing of step (iii) includesserially passing said heat transfer fluid through all of said heattransfer channels defined within said first die set and serially passingsaid heat transfer fluid through all of said heat transfer channelsdefined within said second die set.
 37. The process of claim 32, whereinsaid split parison mold assembly comprises first and second neck moldhalves for defining the external shape of the necks of said parisons,wherein said first and second neck mold halves are coupled to said firstand second dies sets respectively, wherein at least a portion of saidheat transfer channels is defined within said neck mold halves, whereinall of said heat transfer channels that are spaced less than 1 inch fromsaid parison cavity surfaces are defined within said neck mold halves.38. The process of claim 32, wherein said split parison mold assemblycomprises first and second body mold halves for defining the exteriorshape of the bodies of said parisons, wherein said parison cavitysurfaces comprise first and second body-forming surfaces presented bysaid first and second body mold halves respectively, wherein saidbody-forming surfaces define the exterior shape of the bodies of saidparisons, wherein the surface temperature of at least 70 percent of thetotal surface area of said body-forming surfaces is maintained within20° F. of a target body mold surface temperature while said resin isreceived in said parison cavities.
 39. The process of claim 38, whereinthe surface temperature of at least 90 percent of the total surface areaof said body-forming surfaces is maintained within 5° F. of said targetbody mold surface temperature while said resin is received in saidparison cavities.